Electro-mechanical display device

ABSTRACT

There is disclosed an electro-mechanical display device which is actuated by low level power signals which is particularly adapted to be used in readout devices for digital logic circuitry. The display device comprises two segments of resilient film, a first support, one end portion of each of the segments are supported in contiguous relation to one another by the first support, a second support attached to each of the opposite end portions of this film segment, and a means for imparting a relative movement between the first support and the second support wherein indicia located on each of the film segments is moved into and out of view by the relative movement of the first and second supports.

United States atent [19] Feb.5,1974

[ ELECTRO-MECHANICAL DISPLAY DEVICE [75] Inventor: Kenly C. Bugg, Fort Wayne, Ind.

[73] Assignee: Kendick Manufacturing Co., Fort Wayne, Ind.

[22] Filed: Nov. 3, 1972 [21] Appl. N0.: 303,332

[52] US. Cl 40/28 C [51] Int. Cl. G09f 9/30 [58] Field of Search 40/28 C [56] References Cited UNITED STATES PATENTS 3,467,139 9/1969 Richards l37/625.48

3,096,594 7/1963 Skrobisch 40/28 C 3,273,270 9/1966 Skrobisch l i 40/28 C X 3,139,854 7/1964 Hedges et al. 40/65 X 2,426,079 8/1947 Bliss 40/28 C Primary Examiner-Wm. l-l. Grieb Attorney, Agent, or Firm-James P. Hume et a1.

[57] ABSTRACT There is disclosed an electro-mechanical display device which is actuated by low level power signals which is particularly adapted to be used in readout devices for digital logic circuitry. The display device comprises two segments of resilient film, a first support, one end portion of each of the segments are supported in contiguous relation to one another by the first support, a second support attached to each of the opposite end portions of this film segment, and a means for imparting a relative movement between the first support and the second support wherein indicia located on each of the film segments is moved into and out of view by the relative movement of the first and second supports.

6 Claims, 7 Drawing Figures Patenteci Feb. 5, 1974 2 Sheets-Sheet 1 FIG.4

Patented Feb. 5, 1974 2 Sheets-Sheet 2 ELECTRO-MECHANICAL DISPLAY DEVICE BACKGROUND OF THE INVENTION Those concerned with the development of digital readout mechanisms have long recognized the need for an electromechanical display device which may be actuated by low power signals and whose legibility does not wash out in bright light or sunlight environments. In certain environments, such as that encountered in airborne equipment particularly, a reflective readout device is better than one using an illuminated (lamp) segment since the latter are subject to illegibility when there is a large amount of ambient light available. Furthermore, in the aggregate, these lights require large amounts of current to keep them illuminated.

In an attempt to overcome these deficiencies, electromechanical display devices have been developed. One such electro-mechanical display device is disclosed in US. Pat. No. 3,096,594 issued to A. Skrobisch on July 9, 1963. In the Skrobisch patent, an indicator is placed on the rotor of a motor. When the motor is energized, the rotor rotates and the indicator is then brought before a viewing window. When the rotor is again rotated by the actuation of the motor, the indicator is rotated away from the window; and, thus, through selective actuation of the motor, the indicator may be brought into and out of view. A second type of electromechanical indicator utilizes a flexible indicator element such as a tape which may be moved into and out of view from a viewing window. One such indicator is disclosed in US. Pat. No. 3,139,854, issued to ID. Hedges, on July 7, 1964. In this device, an indicator is placed on the flexible tape and the tape is wound onto a drum. As the tape is unwound, the indicator passes before a viewing window thereby exposing the indicator to view. When it is no longer desired to display the indicator, the tape is then wound up and the indicator disappears from the viewing window. A similar type of device is disclosed in US. Pat. No. 3,273,270, issued to A. Skrobisch on Sept. 20, I966. In this device, a flexible element is segmented longitudinally and an indicator is placed on each segment. One side of each segment is attached to a fixed frame while-the other side of each segment is attached to a movable member. By actuating this movable member, the indicator may be brought into and out of view through the movement of the flexible tape, about its pivoting means connected to the fixed frame.

While each of the above prior art types of electromechanical display device has served the purpose, they have not proved entirely satisfactory under all conditions of service since it has been necessary to utilize relatively large amounts of power to actuate the devices and, further, the use of tapes, or other elements which pivot, have inherent friction built into them thus increasing the power requirements and causing wear on the various elements including the tape itself. A further deficiency of these prior art devices is that they have a substantial amount of mass in the movable components and are vulnerable to deleterious effects of shock and vibration. The present invention overcomes these difficulties.

SUMMARY OF THE INVENTION The general purpose of this invention is to provide an electro-mechanical display device which embraces all of the advantages of the similarly employed display devices and possesses none of the aforedescribed limitations. To attain this, the display device of the present invention utilizes a pair of superposed resilient film loops having suitable indicia placed thereon which can be revealed or concealed by appropriate relative frictionless movement of one resilient loop with respect to the other resilient loop. In the preferred embodiment, one end of each of the resilient loops is fixed to one movable frame member while the second ends of each of the resilient loops are fixed to a second movable frame member. As each of the frame members move relative to one another, this causes a rolling action of one film loop against the other film loop thereby causing frictionless movement through the relative rotational movement of one film loop against the other film loop. By moving each end of the film loops, the plane in which the indicator lies remains constant and thus is particularly suitable for use in a digitable readout device. A form which is particularly useful in annunciators provides for movement of only the ends of the resilient loops that are fixed to one, rather than both of the support members, preferably the one which has the contiguous loop ends fixed thereto.

While frictionless motion using two resilient loops has heretofore been utilized in other fields as shown in US. Pat. No. 3,467,139, issued to G.B. Richards on Sept. 16, 1969, this type of movement has not been utilized in electro-mechanical indicator devices.

Therefore, an object of the present invention is to provide an electro-mechanical readout device whose legibility does not was out in bright light or sun environments.

Another object is to provide an electro-mechanical display device which eliminates the use of pivoting means such as those used in shutter and flag type displays.

A further object is to provide an electro-mechanical display device which utilizes a tongue and lip motion wherein a flexible member is rolled to or out of its read or no read position substantially without friction, thus reducing the actuating power requirements to a minimum.

Still another object is to provide an electromechanical display device wherein the indicator is controlled with a push-pull mechanism thus insuring controlled definition and position of the indicator.

Yet another object is to provide an electromechanical display device wherein there is very little mass in the movable components. In addition, opposing forces are applied to the ends of the resilient loop members that are disposed in contiguous rolling relation to each other so that a balanced substantially frictionless support or tongue member supports that end of the loop members. This arrangement increases the resis tance of the device to the deleterious effects of shock and vibration as well.

A still further object is to provide an electromechanical display device utilizing a push-pull motion which precisely moves the opening or closing of the read" or no read indicator surface substantially without friction and without drag to one element or the other.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1, a display device indicated generally by the numeral 10. The display device 10 includes a first support 12 and a second support 14. The first support 12 is adapted to be movable relative to the second support 14 and, furthermore, the second support 14 is adapted to be movable relative to the first support 12, as indicated by the arrows 12a and 14a, respectively. The second support 14 in the preferred embodiment is a generally U- shaped support having a first leg 16 and a second leg 18. Connected between the first support 14 and the first leg 16 of the second support 14 is a loop of resilient film or tape 200. A second resilient loop of film or tape 20b is connected between the first support 12 and the second leg 18 of the second support 14. The two resilient members 20a and 2017 are thus arranged to form two superposed U-shaped loops having the two curved surfaces 21a and 21b respectively. Located on the outer face of each of the resilient members 20a and 2012 at substantially the mid point of the length thereof are the indicia 22a and 22b, respectively. The indicia 22a and 22b may comprise any suitable opaque appropriately colored indicating means such as ink, etc. so disposed that when they are brought into juxtaposition, as shown in FIG. 1, they form a single character such as that shown in FIG. 2.

The display device is adapted to be inserted into a suitable housing (not shown). Located within the housing is a viewing window 26 shown diagrammatically in FIGS. 2 and 3. The viewing window 26 preferably lies in a plane 24 that is disposed in a position normal to the longitudinal axis of the support 12 immediately adjacent the arcuate portions 21a and 21b of the loops of films a and 20b and is adapted to expose the indicia 22a and 22b when they are in the position shown in H6. 1. This position of the indicia will hereinafter he referred to as the read position or condition and is shown in FIG. 2. When the resilient members 20a and 20b are moved in a manner to be described below the indicia 22a and 22b can be rotated away from the viewing window so that only the portion of the resilient members 20a and 20b without the indicia thereon are exposed. This position will hereinafter be referred to as the no read" position or condition and is shown in FIG. 3.

When the first support member 12 is moved to the left, as shown in FIG. 1, while the second support member 14 is kept stationary or moved to the right, as shown in FIG. 1, a rolling motion between the two resilient members 20a and 20b occurs. This rolling motion causes the indicia 22a to move downwardly and the indicia 22b to move upwardly, as viewed in FIG. 1, thereby moving into the bight, or curved portion of the tape, a portion of the surface 21a and 21b of the resilient members 200 and 29b that does not contain the indicia thereon, and simultaneously concealing the indicia, thereby creating the no read condition shown in FIG. 3. It should also be recognized that if the movement of the first support member 12 is equal and opposite to the movement of the second support member 14, (as is preferable) the bight or curved portion of each of the U-shaped resilient members 200 and 20b will remain tangent to the plane 24, and in closely spaced relation to the viewing window 26. However, if the amount of movement of the two support members 12 and 14 differed in magnitude, then the bight portion would move out of association with that plane. Although a preferred embodiment is described below, it will be recognized by one skilled in the art that many different means may be utilized to impart the movement to support members 12 and 14 to effectuate the actuation of the indicia 22a and 22b from their read to no read positions, as shown in FIGS. 2 and 3 respectively.

A plurality of display devices 10 can be arranged so as to provide the formation of either numerals or letters which would then be activated by a driver decoder output in digital logic circuitry. FIGS. 4 and 5 show one arrangement of display devices 10. Referring to FIGS. 4 and 5, the plurality of display devices 10 are arranged in a conventional manner to form the various segments 30 needed to form any numeral from 0 to 9. To accomplish this, it is necessary to have seven such segments. If additional information is required, such as letters, it is then necessary to utilize a further number of segments. In this regard, if fourteen segments were utilized, any letter from A through Z, as well as any number from 0 through 9 could be displayed. While FIG. 4 only shows seven such segments, it will be recognized by one skilled in the art that any number of segments may be employed. Each of the segments 30 comprises one individual display device 10 as shown in FIG. 1. Each segment 30 is disposed in close association with the opaque cover plate 28 which has a viewing window 26 formed therein in association with each segment, showing the presence or absence of a pair of indicia 22a and 22b. For example, in FIG. 4, the numeral 7 is displayed. To effectuate the display of the numeral 7, three of the segments 3b are in a read position, thereby displaying the indicia 22a and 22b while the remaining four of the segments 3% are in their no read position thereby displaying the surfaces 21a and 21b which have no indicia thereon.

FIG. 5 is a side view of the display shown in FIG. 4. From this side view, the positions of the indicia 22a and 22b for each of the segments 31) may be seen. The actuation of the various segments 20 shown in FIGS. 4 and 5 will be explained below in reference to FIGS. 6 and 7.

There is shown in FIGS. 6 and 7 one means for actuating the resilient members 200 and 20b in each of the display devices 10 or in other words, segments 30 of FIGS. 4 and 5. It will be recognized by one skilled in the art that while FIGS. 6 and 7 show only one actuation means, a plurality of these actuation means would be required to effectuate the device shown in FIGS. 4 and 5. In the display device 10 shown in FIGS. 6 and 7, the movable support member 12 is spring biased to the right by a spring 32 abutting the bracket 33 extending between the two armatures 34. Movement of the armatures 34, as will be described below, causes actuation of the support member 12. The limit of travel of the support member 12 is controlled by an abutment member 35 which may be formed integrally with one extremity of the support member 12 and is secured to the bracket 33. The support member 12 is secured to the outer extremities of the armatures 34 by the bracket 33. As shown in FIG. 7, the bracket 33, the abutment 35, and the support member 12 may move to the right as indicated by the arrow 36 under the urging of spring 32. The limit of travel of the support member 12 will occur when the abutment 35 strikes a header 38 which forms a portion of the housing for the display device 10.

The support member 14 as mentioned above in reference to FIG. 1, is generally U-shaped having a first leg 16, a second leg 18, and a base member 40. A lug member 41 projects outwardly from the base of the leg 18 and forms a means for limiting the extent of travel of the second support member 14. The second support member 14 is secured to the outer extremities of a pair of armatures 42 at the base 40 and movement of these armatures 42, as will be described below, causes the actuation of the second support member 14, it being normally urged to the left by spring 32. The limit of travel of the second support member 14 is determined by the contact of the lug member 41 with stop member 44 and the header 45 as indicated by an arrow 46.

The two resilient members a and 2012 are connected between the first support member 12 and the first leg 16 and the second leg 18 of the second support member 14, respectively, and as shown in FIGS. 1 and 7, form two U-shaped loops each of which has one end mounted on the reciprocating first support member 12 so that the end of each of the resilient members 20a and 20b are mounted contiguously. As previously described, the opposite ends of each of the resilient members 20a and 20b are fastened to the first leg 16 and the second leg 18, respectively, of the second support member 14. Located on the outer surface, at the bight portion of each of the resilient members 200 and 20b are indicia 22a and 22b, respectively. As mentioned above, if the first support member 12 and the second support member 14 are given relative motion one to the other, the resilient members 20a and 20b tend to roll one on the other so that a portion of the normally contiguous inner ends 15 will either be exposed or concealed, depending upon which way the relative motion occurs.

Stated more specifically, if the support member 12, as shown in FIG. 6, is moved to the right, relative to the second support member 14, the inner ends 15 will also move to the right thereby causing the indicia 22a and 22b to be moved in that direction. Sufficient movement could remove them from view in the viewing window 26, as shown in FIG. 3, and thereby establish the no read position. However, if at the same time the second support member 14 is moved to the left, the location of the bight will be maintained in substantially the same plane as it was prior to the movement and a greater extent of the two films will be brought into contiguous relation for the same amount of movement of support member 12. Thus, simultaneous opposite movement of support members 12 and 14 is preferred.

As shown in FIG. 6, the armatures 34 and 42 are longitudinally aligned in pairs and each pair is surrounded by a coil 48. The energization of the coils 48 causes movement of the armatures 42 to the right and the armatures 34 to the left, as viewed in FIG. 6. Deenergization of the coils 48 will cause the armatures 42 to move to the left and the armatures 34 to move to the right through the action of the spring member 32.

In FIG. 7, the display device 10 is shown in its read condition. The armatures 42 have been actuated to move the second support member 14 to the extreme position to the right, as indicated by the arrow 46 and the position of the lug 41. Armatures 34 have been actuated to move the first support member 12 to the extreme position to the left as determined by the abutment of the bracket 33 and the header 37. Thus to install the display device 10 as part of a digital read out display system, it is only necessary to connect the coils 48 through the terminals 50 or 52 (which are interconnected) and the common ground terminal 154 to the electrical condition which is being monitored by the display device. The core plugs 56 and 58 are provided between the axially aligned armatures 34 and 42 in each instance to give a full magnetic path through the two armatures in the position shown in FIG. 6. The use of the double armatures also provides a desirable reduction in the air gap.

It will be recognized by one skilled in the art that several different means may be utilized to actuate the first and second support members 12 thereby creating the rolling motion of the resilient members 20a and 20b and this means for imparting this relative motion need not be done through the use of a motor and the motor armature. In one embodiment of the invention, as shown in FIGS. 6 and 7, the movement of the first and second support members 12 and 14 is oriented horizontally but it will be recognized that this need not be the case and the read out display device utilizing a vertical motion may also be employed. In the preferred embodiment, the resilient members 20a and 20b are a flexible film or tape upon which the indicia 22a and 22b are coated. However, other similar resilient members may be utilized.

As stated earlier, the preferred embodiment shown and described is arranged so that there is movement of both film supporting frame members relative to each other. However, in many installations the construction can be substantially simplified by providing for movement of the first support or tongue member 12 only. In such an arrangement the second support member 14 would be constructed as a stationary element fixed with respect to the supporting frame. As indicated earlier, where the display device is to form a part of an annunciator, this type of arrangement will often be fully satisfactory. The necessity of maintaining the bights of the loops of resilient material in substantially the same plane 24 is not normally present in many such applications and such a simplification of the construction, therefore, would be desirable. Obviously, with such an arrangement the indicia 22a and 22b as shown in FIG. 1 would be withdrawn from view by movement to the left of the support member 12.

It should, likewise, be mentioned that although the preferred embodiment disclosed in FIGS. 4 to 7 incorporates a dual solenoid construction, it nevertheless, would be quite possible to utilize a single solenoid to actuate the support member 12, particularly if the support member 14 is of the fixed form just described above. Needless to say, even in a construction in which both support members 12 and 14 are movable, a single solenoid arrangement could be utilized which would simultaneously activate both support members. Such a simplified construction utilizing either the single movable support member or the single solenoid arrangement, or both, would substantially reduce construction costs and would be highly desirable in certain applications. Obviously, many other modifications and variations may be made herein without departing from the spirit and the scope of the present invention as set forth in the appended claims.

What is claimed is:

l. A mechanical display device comprising a first resilient film segment, a second resilient film segment, means for supporting one end portion of each said film segment in contiguous relation, one to the other, and for supporting the opposite end portions so that each resilient film segment has an arcuate portion extending outwardly from the area of contiguous relation of said film segments, means for imparting movement to at least one of said film segments so as to alter the extent of the contiguity of said film segments, and intelligence conveying indicia disposed on the surface of at least said resilient film segment so moved, said indicia being disposed on the portion thereof that is moved into and out of contiguous relation to the corresponding portion of the other said segments by movement of at least one of said film segments.

2. A mechanical display device of the character described in claim 1 further characterized in that said film segments are two superposed Ushaped loops of resilient film having their end portions disposed in substantially parallel relation.

3. A mechanical display device comprising a first resilient film segment, a second resilient film segment, a first support means, one end portion of each said resilient film segment being supported by said first support means in contiguous relation, one to the other, a second support means, the opposite end portion of each of said resilient film segment being supported by said second support means and disposed so that each resilient film segment has an arcuate portion extending outwardly from the area of contiguous relation of said film segments, means for imparting movement to at least one of said support means so as to alter the extent of the contiguity of said film segments. and intelligence conveying indicia disposed on the surface of at least one of said resilient film segments, said indicia being disposed on the portion thereof that is moved into and out of contiguous relation to the corresponding surface of the other of said segments by movement of at least one of said support means.

4. A mechanical display device of the character described in claim 3 further characterized in that said film segments are disposed symmetrically with respect to the arcuate portions thereof.

5. A mechanical display device of the character described in claim 3 further characterized in that said first support means is adapted to move along an axis parallel to said end portions supported in contiguous relation.

6. A mechanical display device of the character described in claim 3 wherein motion is imparted to said first and second support means by an electromagnetically controlled armature means. 

1. A mechanical display device comprising a first resilient film segment, a second resilient film segment, means for supporting one end portion of each said film segment in contiguous relation, one to the other, and for supporting the opposite end portions so that each resilient film segment has an arcuate portion extending outwardly from the area of contiguous relation of said film segments, means for imparting movement to at least one of said film segments so as to alter the extent of the contiguity of said film segments, and intelligence conveying indicia disposed on the surface of at least said resilient film segment so moved, said indicia being disposed on the portion thereof that is moved into and out of contiguous relation to the corresponding portion of the other said segments by movement of at least one of said film segments.
 2. A mechanical display device of the character described in claim 1 further charaCterized in that said film segments are two superposed U-shaped loops of resilient film having their end portions disposed in substantially parallel relation.
 3. A mechanical display device comprising a first resilient film segment, a second resilient film segment, a first support means, one end portion of each said resilient film segment being supported by said first support means in contiguous relation, one to the other, a second support means, the opposite end portion of each of said resilient film segment being supported by said second support means and disposed so that each resilient film segment has an arcuate portion extending outwardly from the area of contiguous relation of said film segments, means for imparting movement to at least one of said support means so as to alter the extent of the contiguity of said film segments. and intelligence conveying indicia disposed on the surface of at least one of said resilient film segments, said indicia being disposed on the portion thereof that is moved into and out of contiguous relation to the corresponding surface of the other of said segments by movement of at least one of said support means.
 4. A mechanical display device of the character described in claim 3 further characterized in that said film segments are disposed symmetrically with respect to the arcuate portions thereof.
 5. A mechanical display device of the character described in claim 3 further characterized in that said first support means is adapted to move along an axis parallel to said end portions supported in contiguous relation.
 6. A mechanical display device of the character described in claim 3 wherein motion is imparted to said first and second support means by an electro-magnetically controlled armature means. 